Gettering issues using MeV ion implantation

MeV implantation hits generated interest as a gettering option in silicon s ince it was established that under the appropriate conditions of irradiatio n fluence, substrate oxygen content, and annealing treatment, at least two distinct regions, denoted as R-p and R-p/2, getter impurities (M. Tamura, T . Ando, O.K., Nucl. Instrum. Methods Phys. Res. B 59/60 (1991) 572; A. Agar wal, K. Christensen, D. Venables, D.M. Maher, G.A. Rozgonyi, Appl. Phys. Le tt. 69 (1996) 3899). In the present work we report on the thermal stability of Fe gettered at R-p due to MeV ion implantation-induced dislocation loop s in Fe contaminated CZ Si wafers, and an activation energy for the release of gettered Fe of 0.80 eV. It has also been determined that, the gettering mechanism in the R-p/2 region in epitaxial Si for high MeV ion doses (appr oximate to 5 x 10(15) Ge cm(-2)) is vacancy-related, since TEM analysis rev ealed 4-11-nm diameter voids. Under the annealing conditions studied, these voids were found to be more efficient at Fe capture than R-p defects. (C) 2000 Published by Elsevier Science S.A. All rights reserved.